MADRID, Spain — Thousands of people from northern Portugal to the heart of Africa donned protective eyeglasses Monday to watch the moon cover the sun like a black plate in a rare and spectacular eclipse.

Office workers and school children met at Madrid’s planetarium beneath a cloudless sky as the moon seemed to bite off the top of the sun, slide in front and leave behind a circle of fire. As the normally blinding light of the Spanish capital dimmed, the air chilled and the crowds whooped and applauded the first such event in 241 years.

“It was a beautiful sight. I won’t see one again,” said 68-year-old Isabel Balset. “I got very emotional and the tears just flowed.”

During an annular eclipse, the moon travels between the Earth and the sun, leaving a bright, fiery rim. The moon was too small to blot out the sun completely, as in a total eclipse, because its elliptical orbit has taken it too far from the Earth.

The rim of fire that appears around the moon glows brighter than the corona that is seen during a total eclipse.

The spectacle began over the North Atlantic just before 11 a.m. local time (5 a.m. EDT), traveling along a narrow band girding almost half the planet. After a 3½-hour stretch traversing northern Portugal and Spain, it moved south across largely deserted parts of Africa, encompassing Algeria, Tunisia, Libya, Chad, Sudan, Ethiopia, Kenya and Somalia.

In Ethiopia, 82-year-old Tebared Tsegahun said members of his Tigray tribe believe that an eclipse is a sign of looming catastrophe.

“It may be a sign of the end of the world or some other great disaster. This is what we believe. I don’t know what you members of the new generation say about it,” Tebared said in Ethiopia’s capital, Addis Ababa. “We will keep praying to survive the danger that will come after it.”

Most of Ethiopia’s 70 million people were not aware of the spectacle. An FM radio station announced the news a couple of hours before the event — not long enough for the news to spread.

In the tiny central African nation of Burundi, residents in the capital, Bujumbura, poured water into buckets and watched the reflection of the eclipse to avoid harming their eyes.

“It looks like sunset, but it is only midday,” said one observer, Thadee Ndaruvukanye. “This is a strong sign from God to show us that he is the most powerful.”

Traditionally, Burundians believe that an eclipse marks a time when the Earth and heaven are linked. It is considered an omen for great misfortune, including poor harvests, the death of precious cattle, an epidemic or conflict.

Burundi’s ancient kings used to gather witch doctors, sorcerers and traditional healers after an eclipse and ordered them to develop charms to protect the country.

Although of far less importance to astronomers than a total eclipse, the event attracted many experts to Spain.

“It was incredible. It became darker and darker, and you could definitely feel the effect, the temperature, the wind and the light,” said astronomy professor Timothy Young of the University of North Dakota. “The moon went right into the center like the bull’s eye. I wished it had lasted for hours instead of just four minutes.”